fix(sync): improve error handling in daemon and add exponential backo…

…ff for server connection

- Added error logging in daemon before re-throwing errors
- Implemented exponential backoff when checking if the server is running
- Addresses issue ActivityWatch/aw-qt#105

aw-sync/src/main.rs

@@ -143,6 +143,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         // Start daemon
         Commands::Daemon {} => {
             info!("Starting daemon...");
+            // TODO: log any errors before re-throwing
             daemon(&client)?;
         }
         // Perform basic sync
@@ -208,14 +209,23 @@ fn main() -> Result<(), Box<dyn Error>> {
 
 fn daemon(client: &AwClient) -> Result<(), Box<dyn Error>> {
     loop {
-        info!("Pulling from all hosts");
-        sync_wrapper::pull_all(client)?;
-
-        info!("Pushing local data");
-        sync_wrapper::push(client)?;
+        if let Err(e) = daemon_sync_cycle(client) {
+            error!("Error during sync cycle: {}", e);
+            // Re-throw the error
+            return Err(e);
+        }
 
         info!("Sync pass done, sleeping for 5 minutes");
-
         std::thread::sleep(std::time::Duration::from_secs(300));
     }
 }
+
+fn daemon_sync_cycle(client: &AwClient) -> Result<(), Box<dyn Error>> {
+    info!("Pulling from all hosts");
+    sync_wrapper::pull_all(client)?;
+
+    info!("Pushing local data");
+    sync_wrapper::push(client)?;
+
+    Ok(())
+}

aw-sync/src/sync_wrapper.rs

@@ -1,6 +1,7 @@
 use std::error::Error;
 use std::fs;
 use std::net::TcpStream;
+use std::time::Duration;
 
 use crate::sync::{sync_run, SyncMode, SyncSpec};
 use aw_client_rust::blocking::AwClient;
@@ -13,16 +14,41 @@ pub fn pull_all(client: &AwClient) -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
+fn wait_for_server(socket_addr: &std::net::SocketAddr) -> Result<(), Box<dyn Error>> {
+    // Check if server is running with exponential backoff
+    let mut retry_delay = Duration::from_millis(100);
+    let max_retry_delay = Duration::from_secs(10);
+    let mut total_wait = Duration::from_secs(0);
+
+    while total_wait < max_retry_delay {
+        match TcpStream::connect_timeout(socket_addr, retry_delay) {
+            Ok(_) => break,
+            Err(_) => {
+                std::thread::sleep(retry_delay);
+                total_wait += retry_delay;
+                retry_delay = std::cmp::min(retry_delay * 2, max_retry_delay);
+            }
+        }
+    }
+
+    if total_wait >= max_retry_delay {
+        return Err(format!(
+            "Local server {} not running after 10 seconds of retrying",
+            socket_addr
+        )
+        .into());
+    }
+
+    Ok(())
+}
+
 pub fn pull(host: &str, client: &AwClient) -> Result<(), Box<dyn Error>> {
     let socket_addrs = client.baseurl.socket_addrs(|| None)?;
     let socket_addr = socket_addrs
         .get(0)
         .ok_or("Unable to resolve baseurl into socket address")?;
 
-    // Check if server is running
-    if TcpStream::connect(socket_addr).is_err() {
-        return Err(format!("Local server {} not running", &client.baseurl).into());
-    }
+    wait_for_server(socket_addr)?;
 
     // Path to the sync folder
     // Sync folder is structured ./{hostname}/{device_id}/test.db